An elite squad of specialist investigators will replace the National Criminal Intelligence Service and the National Crime Squad and take over the investigative functions of the Home Office and Customs and Excise.

A comprehensive strategy with tough new laws to target organised crime was also promised by Home Secretary David Blunkett.

He said, "Organised criminals make their millions from human misery - trafficking in drugs and people, engaging in fraud and extortion.

"They control criminal empires that reach from the other side of the world to the dealer on the street corner. They believe they are beyond the reach of justice and out of our sights. That is not the case - no one should be untraceable and no one should be untouchable.

"This new agency will focus on tracking them down."

Former AM Alison Halford, who lives in Flintshire and was previously assistant chief constable of Merseyside Police, said, "The FBI works well in the US. We must learn from what's going on there.

"We're losing the battle, left, right and centre. The Morecambe Bay situation shows how people smuggling is out of control."

Ms Halford, a former member of North Wales Police Authority, warned some of the agency's funding might be diverted from local police budgets.

"I can't think our Government is going to pay for everything centrally. Somehow the local people have to pay in a roundabout way. Where are they going to find these extra officers and the training?"

She added that the National Assembly for Wales must have a say in the new agency.

The Police Federation, representing rank-and-file officers, said it was worried about the impact on regional forces.

"In principle I agree with bringing together law enforcement agencies to rationalise our response to tackling organised crime across national borders," said Jan Berry, the Federation's chairman for Wales and England.

"What does concern me, however, is where and how this new agency will fit into the Home Secretary's bigger picture of policing. Elitism has no place in British policing.

"I am worried that we will see a skills loss across the 43 police forces in England and Wales, with the cream of the crop being taken to fill places in this new agency.

"We must not get carried away with the glamorised movie image of an FBI offering a total solution to crime. The reality is often quite different."

She said there appeared to be many unanswered questions over the funding of the new agency.

The federation was not convinced modelling the agency on the FBI would deliver the improvements needed in fighting organised crime.

"There are many positive policing methods we can learn from the US but we must recognise that law enforcement there is more fragmented than here in the UK. It is therefore vitally important that this new agency has clear lines of demarcation and fits with our policing structures," said Mrs Berry.

The chief constables of South Wales and Dyfed-Powys supported the Association of Chief Police Officers' view.

Chris Fox, ACPO president, said, "The new agency will provide significant opportunities to fight crime, nationally and internationally, which we know has such a harmful impact on all our communities.

"Combining the expertise, resources and experience of all those working in the crime-fighting agencies will help us build on the work currently under way to deal with very significant crimes often involving hardcore drugs, illegal immigration and gun crime."